Battery voltage. - The voltage on the battery is 12.1V, the starter does not spi

Domin933 51594 32

Treść została przetłumaczona

Zobacz oryginalną wersję tematu

Reply | New topic

#31 20130585 05 Aug 2022 11:24

Bałdyzer Bałdyzer

Level 12

» | Helpful post? (0)

Post #31
20130585 05 Aug 2022 11:24

I have one question. I want to check out two starters I found in the garage. I know how to connect them to the battery, but I have some doubts and I prefer to ask not to damage the battery. I measured the resistance between the mass and the plate where we connect the cable, which we connect to the "plus" during checking. The resistance is so small that there is almost a short circuit (maybe 2-3 ohms). Should it be like that ?
ADVERTISEMENT
#32 20131343 05 Aug 2022 20:08

vodiczka vodiczka

Level 43

» | Helpful post? (0)

Post #32
20131343 05 Aug 2022 20:08

Bałdyzer wrote:
The resistance is so small there is almost a short circuit (maybe 2-3 ohms)

https://nashipoezda.ru/en/logging/kak-proveri...overka-startera-avtomobilya-s-pomoshchyu.html
Link quote: "How to check the starter with a multimeter - check the resistance between the ignition terminal and the relay housing. Check the retention winding of the electromagnetic relay. The resistance should be 2-2.5 ohms."
#33 20131389 05 Aug 2022 20:26

klm787 klm787

Level 36

» | Helpful post? (0)

Post #33
20131389 05 Aug 2022 20:26

Bałdyzer wrote:
Should it be like that

Let a friend take the courage and attach this starter to the battery.
a quote from another topic:

Bałdyzer wrote:
I'm just afraid that if the starter has a short circuit, then by connecting the battery I can damage it

A colleague of the author will not try, he will not find out.
And even such a half-second short circuit will not damage the battery.
Because after correctly connecting such a starter to the battery, you can literally judge in a fraction of a second whether such a starter has started working properly.

First you will hear a hard bendix impact, then starter action.
Create an account, log in and become active in a forum and ads will not appear. You will receive points by participating in discussions.
Join this discussion.

Install the application

Reply | New topic

Report a violation of the law

Topic summary

The discussion revolves around a starting issue with a Citroen C4 1.4 gasoline vehicle, where the starter fails to engage despite the battery showing a resting voltage of 12.1V and dropping to 10.5-10.7V during attempts to start. Participants suggest checking battery terminals, measuring voltage during starting attempts, and considering the battery's age and condition. A voltage below 10V indicates potential battery failure or sulfation. Recommendations include charging the battery with a rectifier, testing with a known good battery, and possibly replacing the battery if it is older than five years or shows signs of damage. The importance of regular battery maintenance and monitoring voltage levels is emphasized.
Summary generated by the language model.

FAQ

TL;DR: A lead-acid starter battery that sags below 10 V during cranking loses ≈70 % of its cold-cranking power; “voltage below 10 V… can mean the battery is to be replaced” [Elektroda, vodiczka, post #17441385] Measure first, buy later. Why it matters: Quick tests can save a €100 tow and pinpoint whether you need a charger, a new battery, or a starter rebuild.

Quick Facts

• Healthy rest voltage (20 °C): 12.6–12.8 V [Bosch, 2022]
• Replace threshold: <10 V under load or <11.8 V after rest [Elektroda, vodiczka, post #17441385]
• Alternator charge range: 13.6–14.5 V (temp-dependent) [Elektroda, vodiczka, post #17444874]
• Starter solenoid coil: 2–2.5 Ω between S-terminal and body [Elektroda, vodiczka, post #20131343]
• 60 Ah replacement cost: €70–€120 (EU retail) [ADAC, 2023]

1. What resting voltage shows a fully charged 12 V car battery?

12.6–12.8 V at 20 °C means 100 % state of charge [Bosch, 2022]. Below 12.2 V indicates less than 50 % charge and risk of sulphation.

2. How low can voltage drop during start before I condemn the battery?

If clamp voltage falls under 10 V while cranking, the battery is either deeply discharged or sulphated and near end-of-life [Elektroda, vodiczka, post #17441385]

3. My meter shows 10.7 V before cranking; is that a shorted cell?

Yes. “10.7 V proves a short circuit in the cell, nothing more” [Elektroda, Strumien swiadomosci swia, #17441456]. Replace rather than recharge.

4. How do I measure voltage alone without a helper?

Plug a cigarette-lighter voltmeter, turn the key, and read the display [Elektroda, vodiczka, post #17441355]

5. Three-step check: Is it the battery or the starter?

Measure rest voltage.
Measure during crank; <10 V points to battery.
Jump with a known-good battery; if starter turns, original battery is bad [Elektroda, kokapetyl, post #17441350]

6. What charger spec is enough for occasional top-ups?

A simple 12 V, 6 A automatic charger is adequate for batteries up to 70 Ah [Elektroda, Gienek, post #17441886]

7. How long should I charge to desulphate a tired unit?

Charge to 14.6–14.7 V, then keep 0.4–0.5 A until 15.2 V; this low-current finish can dissolve soft sulphate [Elektroda, vodiczka, post #17447235]

8. Is jump-starting for a few seconds harmful?

No. A half-second short test or cable jump will not damage a healthy battery [Elektroda, klm787, post #20131389]

9. Why did the car start fine yesterday but not today?

Modern batteries can fail abruptly; plates shed mass, causing an internal short that drops voltage overnight [Elektroda, vodiczka, post #17441546]

10. How often should I recharge a seldom-used battery?

Top up every 1–3 months; self-discharge accelerates above 20 °C [Elektroda, kris8888, post #17445785]

11. What’s the safe alternator charging voltage?

Most vehicles regulate between 13.6 V (hot) and 14.5 V (cold) to limit gassing [Elektroda, vodiczka, post #17444874] Over 15 V risks water loss.

12. Can storing a battery indoors kill it?

Yes. A six-month idle battery dropped to 0.1 V due to self-discharge and sulphation [Elektroda, isabelll, post #17445719] Store in a cool place and recharge quarterly.

13. What resistance should I read on a loose starter’s solenoid?

2–2.5 Ω between the ignition terminal (S) and the housing indicates a good hold coil [Elektroda, vodiczka, post #20131343]

14. Edge case: Why does the indicator “green eye” lie?

It samples only one cell; stuck balls or low electrolyte can falsely show ‘OK’ while other cells sulphate [Elektroda, kris8888, post #17449706]

15. Does frequent short-trip driving shorten battery life?

Yes. Repeated 15-minute stops deplete more charge than the alternator can restore, accelerating sulphation [Elektroda, vodiczka, post #17447235]

16. When is it cheaper to buy a new battery than a charger?

If your existing unit shows <10 V and is 5 + years old, a €80 charger won’t revive it; a €90–€100 new battery is wiser [Elektroda, Strumien swiadomosci swia, #17441467; ADAC, 2023].